/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ToUnknownStream.java,v 1.3 2005/09/28 13:49:08 pvedula Exp $
 */
package com.sun.org.apache.xml.internal.serializer;

import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.util.Properties;
import java.util.Vector;

import javax.xml.transform.SourceLocator;
import javax.xml.transform.Transformer;

import org.w3c.dom.Node;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;


/**
 * This class wraps another SerializationHandler. The wrapped object will either
 * handler XML or HTML, which is not known until a little later when the first XML
 * tag is seen.  If the first tag is <html> then the wrapped object is an HTML
 * handler, otherwise it is an XML handler.
 *
 * This class effectively caches the first few calls to it then passes them
 * on to the wrapped handler (once it exists).  After that subsequent calls a
 * simply passed directly to the wrapped handler.
 *
 * The user of this class doesn't know if the output is ultimatley XML or HTML.
 *
 * This class is not a public API, it is public because it is used within Xalan.
 *
 * @xsl.usage internal
 */
public final class ToUnknownStream extends SerializerBase {

  /**
   * The wrapped handler, initially XML but possibly switched to HTML
   */
  private SerializationHandler m_handler;

  /**
   * A String with no characters
   */
  private static final String EMPTYSTRING = "";

  /**
   * true if the underlying handler (XML or HTML) is fully initialized
   */
  private boolean m_wrapped_handler_not_initialized = false;


  /**
   * the prefix of the very first tag in the document
   */
  private String m_firstElementPrefix;
  /**
   * the element name (including any prefix) of the very first tag in the document
   */
  private String m_firstElementName;

  /**
   * the namespace URI associated with the first element
   */
  private String m_firstElementURI;

  /**
   * the local name (no prefix) associated with the first element
   */
  private String m_firstElementLocalName = null;

  /**
   * true if the first tag has been emitted to the wrapped handler
   */
  private boolean m_firstTagNotEmitted = true;

  /**
   * A collection of namespace URI's (only for first element).
   * _namespacePrefix has the matching prefix for these URI's
   */
  private Vector m_namespaceURI = null;
  /**
   * A collection of namespace Prefix (only for first element)
   * _namespaceURI has the matching URIs for these prefix'
   */
  private Vector m_namespacePrefix = null;

  /**
   * true if startDocument() was called before the underlying handler
   * was initialized
   */
  private boolean m_needToCallStartDocument = false;
  /**
   * true if setVersion() was called before the underlying handler
   * was initialized
   */
  private boolean m_setVersion_called = false;
  /**
   * true if setDoctypeSystem() was called before the underlying handler
   * was initialized
   */
  private boolean m_setDoctypeSystem_called = false;
  /**
   * true if setDoctypePublic() was called before the underlying handler
   * was initialized
   */
  private boolean m_setDoctypePublic_called = false;
  /**
   * true if setMediaType() was called before the underlying handler
   * was initialized
   */
  private boolean m_setMediaType_called = false;

  /**
   * Default constructor.
   * Initially this object wraps an XML Stream object, so _handler is never null.
   * That may change later to an HTML Stream object.
   */
  public ToUnknownStream() {
    m_handler = new ToXMLStream();
  }

  /**
   * @return the wrapped XML or HTML handler
   * @see Serializer#asContentHandler()
   */
  public ContentHandler asContentHandler() throws IOException {
        /* don't return the real handler ( m_handler ) because
         * that would expose the real handler to the outside.
         * Keep m_handler private so it can be internally swapped
         * to an HTML handler.
         */
    return this;
  }

  /**
   * @see SerializationHandler#close()
   */
  public void close() {
    m_handler.close();
  }

  /**
   * @return the properties of the underlying handler
   * @see Serializer#getOutputFormat()
   */
  public Properties getOutputFormat() {
    return m_handler.getOutputFormat();
  }

  /**
   * @return the OutputStream of the underlying XML or HTML handler
   * @see Serializer#getOutputStream()
   */
  public OutputStream getOutputStream() {
    return m_handler.getOutputStream();
  }

  /**
   * @return the Writer of the underlying XML or HTML handler
   * @see Serializer#getWriter()
   */
  public Writer getWriter() {
    return m_handler.getWriter();
  }

  /**
   * passes the call on to the underlying HTML or XML handler
   *
   * @return ???
   * @see Serializer#reset()
   */
  public boolean reset() {
    return m_handler.reset();
  }

  /**
   * Converts the DOM node to output
   *
   * @param node the DOM node to transform to output
   * @see DOMSerializer#serialize(Node)
   */
  public void serialize(Node node) throws IOException {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.serialize(node);
  }

  /**
   * @see SerializationHandler#setEscaping(boolean)
   */
  public boolean setEscaping(boolean escape) throws SAXException {
    return m_handler.setEscaping(escape);
  }

  /**
   * Set the properties of the handler
   *
   * @param format the output properties to set
   * @see Serializer#setOutputFormat(Properties)
   */
  public void setOutputFormat(Properties format) {
    m_handler.setOutputFormat(format);
  }

  /**
   * Sets the output stream to write to
   *
   * @param output the OutputStream to write to
   * @see Serializer#setOutputStream(OutputStream)
   */
  public void setOutputStream(OutputStream output) {
    m_handler.setOutputStream(output);
  }

  /**
   * Sets the writer to write to
   *
   * @param writer the writer to write to
   * @see Serializer#setWriter(Writer)
   */
  public void setWriter(Writer writer) {
    m_handler.setWriter(writer);
  }

  /**
   * Adds an attribute to the currenly open tag
   *
   * @param uri the URI of a namespace
   * @param localName the attribute name, without prefix
   * @param rawName the attribute name, with prefix (if any)
   * @param type the type of the attribute, typically "CDATA"
   * @param value the value of the parameter
   * @param XSLAttribute true if this attribute is coming from an xsl:attribute element
   * @see ExtendedContentHandler#addAttribute(String, String, String, String, String)
   */
  public void addAttribute(
      String uri,
      String localName,
      String rawName,
      String type,
      String value)
      throws SAXException {
    addAttribute(uri, localName, rawName, type, value, false);
  }

  /**
   * Adds an attribute to the currenly open tag
   *
   * @param uri the URI of a namespace
   * @param localName the attribute name, without prefix
   * @param rawName the attribute name, with prefix (if any)
   * @param type the type of the attribute, typically "CDATA"
   * @param value the value of the parameter
   * @param XSLAttribute true if this attribute is coming from an xsl:attribute element
   * @see ExtendedContentHandler#addAttribute(String, String, String, String, String)
   */
  public void addAttribute(
      String uri,
      String localName,
      String rawName,
      String type,
      String value,
      boolean XSLAttribute)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.addAttribute(uri, localName, rawName, type, value, XSLAttribute);
  }

  /**
   * Adds an attribute to the currenly open tag
   *
   * @param rawName the attribute name, with prefix (if any)
   * @param value the value of the parameter
   * @see ExtendedContentHandler#addAttribute(String, String)
   */
  public void addAttribute(String rawName, String value) {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.addAttribute(rawName, value);

  }

  /**
   * Adds a unique attribute to the currenly open tag
   */
  public void addUniqueAttribute(String rawName, String value, int flags)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.addUniqueAttribute(rawName, value, flags);

  }

  /**
   * Converts the String to a character array and calls the SAX method
   * characters(char[],int,int);
   *
   * @see ExtendedContentHandler#characters(String)
   */
  public void characters(String chars) throws SAXException {
    final int length = chars.length();
    if (length > m_charsBuff.length) {
      m_charsBuff = new char[length * 2 + 1];
    }
    chars.getChars(0, length, m_charsBuff, 0);
    this.characters(m_charsBuff, 0, length);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see ExtendedContentHandler#endElement(String)
   */
  public void endElement(String elementName) throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.endElement(elementName);
  }


  /**
   * @param prefix The prefix that maps to the URI
   * @param uri The URI for the namespace
   * @see org.xml.sax.ContentHandler#startPrefixMapping(String, String)
   */
  public void startPrefixMapping(String prefix, String uri) throws SAXException {
    this.startPrefixMapping(prefix, uri, true);
  }

  /**
   * This method is used when a prefix/uri namespace mapping
   * is indicated after the element was started with a
   * startElement() and before and endElement().
   * startPrefixMapping(prefix,uri) would be used before the
   * startElement() call.
   *
   * @param uri the URI of the namespace
   * @param prefix the prefix associated with the given URI.
   * @see ExtendedContentHandler#namespaceAfterStartElement(String, String)
   */
  public void namespaceAfterStartElement(String prefix, String uri)
      throws SAXException {
    // hack for XSLTC with finding URI for default namespace
    if (m_firstTagNotEmitted && m_firstElementURI == null && m_firstElementName != null) {
      String prefix1 = getPrefixPart(m_firstElementName);
      if (prefix1 == null && EMPTYSTRING.equals(prefix)) {
        // the elements URI is not known yet, and it
        // doesn't have a prefix, and we are currently
        // setting the uri for prefix "", so we have
        // the uri for the element... lets remember it
        m_firstElementURI = uri;
      }
    }
    startPrefixMapping(prefix, uri, false);
  }

  public boolean startPrefixMapping(String prefix, String uri, boolean shouldFlush)
      throws SAXException {
    boolean pushed = false;
    if (m_firstTagNotEmitted) {
      if (m_firstElementName != null && shouldFlush) {
                /* we've already seen a startElement, and this is a prefix mapping
                 * for the up coming element, so flush the old element
                 * then send this event on its way.
                 */
        flush();
        pushed = m_handler.startPrefixMapping(prefix, uri, shouldFlush);
      } else {
        if (m_namespacePrefix == null) {
          m_namespacePrefix = new Vector();
          m_namespaceURI = new Vector();
        }
        m_namespacePrefix.addElement(prefix);
        m_namespaceURI.addElement(uri);

        if (m_firstElementURI == null) {
          if (prefix.equals(m_firstElementPrefix)) {
            m_firstElementURI = uri;
          }
        }
      }

    } else {
      pushed = m_handler.startPrefixMapping(prefix, uri, shouldFlush);
    }
    return pushed;
  }

  /**
   * This method cannot be cached because default is different in
   * HTML and XML (we need more than a boolean).
   */

  public void setVersion(String version) {
    m_handler.setVersion(version);

    // Cache call to setVersion()
    //       super.setVersion(version);
    m_setVersion_called = true;
  }

  /**
   * @see org.xml.sax.ContentHandler#startDocument()
   */
  public void startDocument() throws SAXException {
    m_needToCallStartDocument = true;
  }


  public void startElement(String qName) throws SAXException {
    this.startElement(null, null, qName, null);
  }

  public void startElement(String namespaceURI, String localName, String qName)
      throws SAXException {
    this.startElement(namespaceURI, localName, qName, null);
  }

  public void startElement(
      String namespaceURI,
      String localName,
      String elementName,
      Attributes atts) throws SAXException {

    if (m_needToCallSetDocumentInfo) {
      super.setDocumentInfo();
      m_needToCallSetDocumentInfo = false;
    }

        /* we are notified of the start of an element */
    if (m_firstTagNotEmitted) {
            /* we have not yet sent the first element on its way */
      if (m_firstElementName != null) {
                /* this is not the first element, but a later one.
                 * But we have the old element pending, so flush it out,
                 * then send this one on its way.
                 */
        flush();
        m_handler.startElement(namespaceURI, localName, elementName, atts);
      } else {
                /* this is the very first element that we have seen,
                 * so save it for flushing later.  We may yet get to know its
                 * URI due to added attributes.
                 */

        m_wrapped_handler_not_initialized = true;
        m_firstElementName = elementName;

        // null if not known
        m_firstElementPrefix = getPrefixPartUnknown(elementName);

        // null if not known
        m_firstElementURI = namespaceURI;

        // null if not known
        m_firstElementLocalName = localName;

        if (m_tracer != null) {
          firePseudoElement(elementName);
        }

                /* we don't want to call our own addAttributes, which
                 * merely delegates to the wrapped handler, but we want to
                 * add these attributes to m_attributes. So me must call super.
                 * addAttributes() In this case m_attributes is only used for the
                 * first element, after that this class totally delegates to the
                 * wrapped handler which is either XML or HTML.
                 */
        if (atts != null) {
          super.addAttributes(atts);
        }

        // if there are attributes, then lets make the flush()
        // call the startElement on the handler and send the
        // attributes on their way.
        if (atts != null) {
          flush();
        }

      }
    } else {
      // this is not the first element, but a later one, so just
      // send it on its way.
      m_handler.startElement(namespaceURI, localName, elementName, atts);
    }
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see ExtendedLexicalHandler#comment(String)
   */
  public void comment(String comment) throws SAXException {
    if (m_firstTagNotEmitted && m_firstElementName != null) {
      emitFirstTag();
    } else if (m_needToCallStartDocument) {
      m_handler.startDocument();
      m_needToCallStartDocument = false;
    }

    m_handler.comment(comment);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getDoctypePublic()
   */
  public String getDoctypePublic() {

    return m_handler.getDoctypePublic();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getDoctypeSystem()
   */
  public String getDoctypeSystem() {
    return m_handler.getDoctypeSystem();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getEncoding()
   */
  public String getEncoding() {
    return m_handler.getEncoding();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getIndent()
   */
  public boolean getIndent() {
    return m_handler.getIndent();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getIndentAmount()
   */
  public int getIndentAmount() {
    return m_handler.getIndentAmount();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getMediaType()
   */
  public String getMediaType() {
    return m_handler.getMediaType();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getOmitXMLDeclaration()
   */
  public boolean getOmitXMLDeclaration() {
    return m_handler.getOmitXMLDeclaration();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getStandalone()
   */
  public String getStandalone() {
    return m_handler.getStandalone();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#getVersion()
   */
  public String getVersion() {
    return m_handler.getVersion();
  }

  /**
   * @see XSLOutputAttributes#setDoctype(String, String)
   */
  public void setDoctype(String system, String pub) {
    m_handler.setDoctypePublic(pub);
    m_handler.setDoctypeSystem(system);
  }

  /**
   * Set the doctype in the underlying XML handler. Remember that this method
   * was called, just in case we need to transfer this doctype to an HTML handler
   *
   * @param doctype the public doctype to set
   * @see XSLOutputAttributes#setDoctypePublic(String)
   */
  public void setDoctypePublic(String doctype) {
    m_handler.setDoctypePublic(doctype);
    m_setDoctypePublic_called = true;
  }

  /**
   * Set the doctype in the underlying XML handler. Remember that this method
   * was called, just in case we need to transfer this doctype to an HTML handler
   *
   * @param doctype the system doctype to set
   * @see XSLOutputAttributes#setDoctypeSystem(String)
   */
  public void setDoctypeSystem(String doctype) {
    m_handler.setDoctypeSystem(doctype);
    m_setDoctypeSystem_called = true;
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#setEncoding(String)
   */
  public void setEncoding(String encoding) {
    m_handler.setEncoding(encoding);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#setIndent(boolean)
   */
  public void setIndent(boolean indent) {
    m_handler.setIndent(indent);
  }

  /**
   * Pass the call on to the underlying handler
   */
  public void setIndentAmount(int value) {
    m_handler.setIndentAmount(value);
  }

  /**
   * @see XSLOutputAttributes#setMediaType(String)
   */
  public void setMediaType(String mediaType) {
    m_handler.setMediaType(mediaType);
    m_setMediaType_called = true;
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#setOmitXMLDeclaration(boolean)
   */
  public void setOmitXMLDeclaration(boolean b) {
    m_handler.setOmitXMLDeclaration(b);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see XSLOutputAttributes#setStandalone(String)
   */
  public void setStandalone(String standalone) {
    m_handler.setStandalone(standalone);
  }

  /**
   * @see XSLOutputAttributes#setVersion(String)
   */

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.DeclHandler#attributeDecl(String, String, String, String, String)
   */
  public void attributeDecl(
      String arg0,
      String arg1,
      String arg2,
      String arg3,
      String arg4)
      throws SAXException {
    m_handler.attributeDecl(arg0, arg1, arg2, arg3, arg4);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.DeclHandler#elementDecl(String, String)
   */
  public void elementDecl(String arg0, String arg1) throws SAXException {
    if (m_firstTagNotEmitted) {
      emitFirstTag();
    }
    m_handler.elementDecl(arg0, arg1);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.DeclHandler#externalEntityDecl(String, String, String)
   */
  public void externalEntityDecl(
      String name,
      String publicId,
      String systemId)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.externalEntityDecl(name, publicId, systemId);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.DeclHandler#internalEntityDecl(String, String)
   */
  public void internalEntityDecl(String arg0, String arg1)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.internalEntityDecl(arg0, arg1);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#characters(char[], int, int)
   */
  public void characters(char[] characters, int offset, int length)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }

    m_handler.characters(characters, offset, length);

  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#endDocument()
   */
  public void endDocument() throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }

    m_handler.endDocument();


  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#endElement(String, String, String)
   */
  public void endElement(String namespaceURI, String localName, String qName)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
      if (namespaceURI == null && m_firstElementURI != null) {
        namespaceURI = m_firstElementURI;
      }

      if (localName == null && m_firstElementLocalName != null) {
        localName = m_firstElementLocalName;
      }
    }

    m_handler.endElement(namespaceURI, localName, qName);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#endPrefixMapping(String)
   */
  public void endPrefixMapping(String prefix) throws SAXException {
    m_handler.endPrefixMapping(prefix);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#ignorableWhitespace(char[], int, int)
   */
  public void ignorableWhitespace(char[] ch, int start, int length)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }
    m_handler.ignorableWhitespace(ch, start, length);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#processingInstruction(String, String)
   */
  public void processingInstruction(String target, String data)
      throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }

    m_handler.processingInstruction(target, data);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#setDocumentLocator(Locator)
   */
  public void setDocumentLocator(Locator locator) {
    super.setDocumentLocator(locator);
    m_handler.setDocumentLocator(locator);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ContentHandler#skippedEntity(String)
   */
  public void skippedEntity(String name) throws SAXException {
    m_handler.skippedEntity(name);
  }


  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.LexicalHandler#comment(char[], int, int)
   */
  public void comment(char[] ch, int start, int length) throws SAXException {
    if (m_firstTagNotEmitted) {
      flush();
    }

    m_handler.comment(ch, start, length);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.LexicalHandler#endCDATA()
   */
  public void endCDATA() throws SAXException {

    m_handler.endCDATA();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.LexicalHandler#endDTD()
   */
  public void endDTD() throws SAXException {

    m_handler.endDTD();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.LexicalHandler#endEntity(String)
   */
  public void endEntity(String name) throws SAXException {
    if (m_firstTagNotEmitted) {
      emitFirstTag();
    }
    m_handler.endEntity(name);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.LexicalHandler#startCDATA()
   */
  public void startCDATA() throws SAXException {
    m_handler.startCDATA();
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.LexicalHandler#startDTD(String, String, String)
   */
  public void startDTD(String name, String publicId, String systemId)
      throws SAXException {
    m_handler.startDTD(name, publicId, systemId);
  }

  /**
   * Pass the call on to the underlying handler
   *
   * @see org.xml.sax.ext.LexicalHandler#startEntity(String)
   */
  public void startEntity(String name) throws SAXException {
    m_handler.startEntity(name);
  }

  /**
   * Initialize the wrapped output stream (XML or HTML).
   * If the stream handler should be HTML, then replace the XML handler with
   * an HTML handler. After than send the starting method calls that were cached
   * to the wrapped handler.
   */
  private void initStreamOutput() throws SAXException {

    // Try to rule out if this is an not to be an HTML document based on prefix
    boolean firstElementIsHTML = isFirstElemHTML();

    if (firstElementIsHTML) {
      // create an HTML output handler, and initialize it

      // keep a reference to the old handler, ... it will soon be gone
      SerializationHandler oldHandler = m_handler;

            /* We have to make sure we get an output properties with the proper
             * defaults for the HTML method.  The easiest way to do this is to
             * have the OutputProperties class do it.
             */

      Properties htmlProperties =
          OutputPropertiesFactory.getDefaultMethodProperties(Method.HTML);
      Serializer serializer =
          SerializerFactory.getSerializer(htmlProperties);

      // The factory should be returning a ToStream
      // Don't know what to do if it doesn't
      // i.e. the user has over-ridden the content-handler property
      // for html
      m_handler = (SerializationHandler) serializer;
      //m_handler = new ToHTMLStream();

      Writer writer = oldHandler.getWriter();

      if (null != writer) {
        m_handler.setWriter(writer);
      } else {
        OutputStream os = oldHandler.getOutputStream();

        if (null != os) {
          m_handler.setOutputStream(os);
        }
      }

      // need to copy things from the old handler to the new one here

      //            if (_setVersion_called)
      //            {
      m_handler.setVersion(oldHandler.getVersion());
      //            }
      //            if (_setDoctypeSystem_called)
      //            {
      m_handler.setDoctypeSystem(oldHandler.getDoctypeSystem());
      //            }
      //            if (_setDoctypePublic_called)
      //            {
      m_handler.setDoctypePublic(oldHandler.getDoctypePublic());
      //            }
      //            if (_setMediaType_called)
      //            {
      m_handler.setMediaType(oldHandler.getMediaType());
      //            }

      m_handler.setTransformer(oldHandler.getTransformer());
    }

        /* Now that we have a real wrapped handler (XML or HTML) lets
         * pass any cached calls to it
         */
    // Call startDocument() if necessary
    if (m_needToCallStartDocument) {
      m_handler.startDocument();
      m_needToCallStartDocument = false;
    }

    // the wrapped handler is now fully initialized
    m_wrapped_handler_not_initialized = false;
  }

  private void emitFirstTag() throws SAXException {
    if (m_firstElementName != null) {
      if (m_wrapped_handler_not_initialized) {
        initStreamOutput();
        m_wrapped_handler_not_initialized = false;
      }
      // Output first tag
      m_handler.startElement(m_firstElementURI, null, m_firstElementName, m_attributes);
      // don't need the collected attributes of the first element anymore.
      m_attributes = null;

      // Output namespaces of first tag
      if (m_namespacePrefix != null) {
        final int n = m_namespacePrefix.size();
        for (int i = 0; i < n; i++) {
          final String prefix =
              (String) m_namespacePrefix.elementAt(i);
          final String uri = (String) m_namespaceURI.elementAt(i);
          m_handler.startPrefixMapping(prefix, uri, false);
        }
        m_namespacePrefix = null;
        m_namespaceURI = null;
      }
      m_firstTagNotEmitted = false;
    }
  }

  /**
   * Utility function for calls to local-name().
   *
   * Don't want to override static function on SerializerBase
   * So added Unknown suffix to method name.
   */
  private String getLocalNameUnknown(String value) {
    int idx = value.lastIndexOf(':');
    if (idx >= 0) {
      value = value.substring(idx + 1);
    }
    idx = value.lastIndexOf('@');
    if (idx >= 0) {
      value = value.substring(idx + 1);
    }
    return (value);
  }

  /**
   * Utility function to return prefix
   *
   * Don't want to override static function on SerializerBase
   * So added Unknown suffix to method name.
   */
  private String getPrefixPartUnknown(String qname) {
    final int index = qname.indexOf(':');
    return (index > 0) ? qname.substring(0, index) : EMPTYSTRING;
  }

  /**
   * Determine if the firts element in the document is <html> or <HTML>
   * This uses the cached first element name, first element prefix and the
   * cached namespaces from previous method calls
   *
   * @return true if the first element is an opening <html> tag
   */
  private boolean isFirstElemHTML() {
    boolean isHTML;

    // is the first tag html, not considering the prefix ?
    isHTML =
        getLocalNameUnknown(m_firstElementName).equalsIgnoreCase("html");

    // Try to rule out if this is not to be an HTML document based on URI
    if (isHTML
        && m_firstElementURI != null
        && !EMPTYSTRING.equals(m_firstElementURI)) {
      // the <html> element has a non-trivial namespace
      isHTML = false;
    }
    // Try to rule out if this is an not to be an HTML document based on prefix
    if (isHTML && m_namespacePrefix != null) {
            /* the first element has a name of "html", but lets check the prefix.
             * If the prefix points to a namespace with a URL that is not ""
             * then the doecument doesn't start with an <html> tag, and isn't html
             */
      final int max = m_namespacePrefix.size();
      for (int i = 0; i < max; i++) {
        final String prefix = (String) m_namespacePrefix.elementAt(i);
        final String uri = (String) m_namespaceURI.elementAt(i);

        if (m_firstElementPrefix != null
            && m_firstElementPrefix.equals(prefix)
            && !EMPTYSTRING.equals(uri)) {
          // The first element has a prefix, so it can't be <html>
          isHTML = false;
          break;
        }
      }

    }
    return isHTML;
  }

  /**
   * @see Serializer#asDOMSerializer()
   */
  public DOMSerializer asDOMSerializer() throws IOException {
    return m_handler.asDOMSerializer();
  }

  /**
   * @param URI_and_localNames Vector a list of pairs of URI/localName specified in the
   * cdata-section-elements attribute.
   * @see SerializationHandler#setCdataSectionElements(java.util.Vector)
   */
  public void setCdataSectionElements(Vector URI_and_localNames) {
    m_handler.setCdataSectionElements(URI_and_localNames);
  }

  /**
   * @see ExtendedContentHandler#addAttributes(org.xml.sax.Attributes)
   */
  public void addAttributes(Attributes atts) throws SAXException {
    m_handler.addAttributes(atts);
  }

  /**
   * Get the current namespace mappings.
   * Simply returns the mappings of the wrapped handler.
   *
   * @see ExtendedContentHandler#getNamespaceMappings()
   */
  public NamespaceMappings getNamespaceMappings() {
    NamespaceMappings mappings = null;
    if (m_handler != null) {
      mappings = m_handler.getNamespaceMappings();
    }
    return mappings;
  }

  /**
   * @see SerializationHandler#flushPending()
   */
  public void flushPending() throws SAXException {

    flush();

    m_handler.flushPending();
  }

  private void flush() {
    try {
      if (m_firstTagNotEmitted) {
        emitFirstTag();
      }
      if (m_needToCallStartDocument) {
        m_handler.startDocument();
        m_needToCallStartDocument = false;
      }
    } catch (SAXException e) {
      throw new RuntimeException(e.toString());
    }


  }

  /**
   * @see ExtendedContentHandler#getPrefix
   */
  public String getPrefix(String namespaceURI) {
    return m_handler.getPrefix(namespaceURI);
  }

  /**
   * @see ExtendedContentHandler#entityReference(java.lang.String)
   */
  public void entityReference(String entityName) throws SAXException {
    m_handler.entityReference(entityName);
  }

  /**
   * @see ExtendedContentHandler#getNamespaceURI(java.lang.String, boolean)
   */
  public String getNamespaceURI(String qname, boolean isElement) {
    return m_handler.getNamespaceURI(qname, isElement);
  }

  public String getNamespaceURIFromPrefix(String prefix) {
    return m_handler.getNamespaceURIFromPrefix(prefix);
  }

  public void setTransformer(Transformer t) {
    m_handler.setTransformer(t);
    if ((t instanceof SerializerTrace) &&
        (((SerializerTrace) t).hasTraceListeners())) {
      m_tracer = (SerializerTrace) t;
    } else {
      m_tracer = null;
    }
  }

  public Transformer getTransformer() {
    return m_handler.getTransformer();
  }

  /**
   * @see SerializationHandler#setContentHandler(org.xml.sax.ContentHandler)
   */
  public void setContentHandler(ContentHandler ch) {
    m_handler.setContentHandler(ch);
  }

  /**
   * This method is used to set the source locator, which might be used to
   * generated an error message.
   *
   * @param locator the source locator
   * @see ExtendedContentHandler#setSourceLocator(javax.xml.transform.SourceLocator)
   */
  public void setSourceLocator(SourceLocator locator) {
    m_handler.setSourceLocator(locator);
  }

  protected void firePseudoElement(String elementName) {

    if (m_tracer != null) {
      StringBuffer sb = new StringBuffer();

      sb.append('<');
      sb.append(elementName);

      // convert the StringBuffer to a char array and
      // emit the trace event that these characters "might"
      // be written
      char ch[] = sb.toString().toCharArray();
      m_tracer.fireGenerateEvent(
          SerializerTrace.EVENTTYPE_OUTPUT_PSEUDO_CHARACTERS,
          ch,
          0,
          ch.length);
    }
  }
}
